EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1154 AM EDT FRI OCT 03 2014 VALID 12Z MON OCT 06 2014 - 12Z FRI OCT 10 2014 TWO IMPORTANT ASPECTS OF THE FLOW ACROSS CENTRAL NORTH AMERICA AT THE MEDIUM RANGE ARE STILL IN CONTENTION AMONG THE VARIOUS MODEL SOLUTIONS: THE COHERENCE OF THE FLOW ON THE BACKSIDE OF THE EASTERN TROUGH, AND THE FATE OF THE REMNANTS OF SIMON. WITH REGARD TO THE FLOW IN THE EAST, THE OPERATIONAL GFS IS THE STANDOUT WITH NO INDICATION OF SPLITTING ALONG THE MISSISSIPPI VALLEY. HOWEVER, THE PARALLEL GFS--WHICH FEATURES SOME IMPORTANT RETOOLINGS OVER VERSIONS HERETOFORE--IS VERY MUCH IN SYNC WITH THE SPLITTY 00Z/03 ECMWF AND CANADIAN SOLUTIONS. THE CANADIAN IS ON ITS OWN WITH A SIGNIFICANT PHASING OF NORTHERN STREAM ENERGY IN THE WAKE OF THE SPLIT, SO RELIED ON THE ECENS MEAN AS A MORE BALANCED FACSIMILE OF THE ECMWF AND PARALLEL GFS. THE FATE OF TROPICAL STORM SIMON--CURRENTLY WEST OF MEXICO--RESTS UPON TWO CRITICAL PATHWAYS. FIRST, HOW FAR WEST DOES THE STORM TRACK BEFORE IT RECURVES. THE ECMWF IS ON THE FAR LEFT SIDE OF THE GUIDANCE, WITH THE GFS--AND GFS PARALLEL--TAKING UP THE EASTERN END. SECOND, WHAT WILL THE NATURE BE OF ANY INTERACTION WITH THE WEAK SPLIT OFF THE UNITED STATES WEST COAST. THE DETERMINISTIC RANGE OF POSSIBILITIES FROM THE 00Z/03 DATA CYCLE INCLUDED A VIGOROUS BINARY INTERACTION OVER SOUTHERN CALIFORNIA (NAVGEM), A FAST RECURVATURE AND ATTENDANT HEAVY RAINFALL THREAT FOR NEW MEXICO AND WESTERN TEXAS (GFS PARALLEL), AND MANY SOLUTIONS THAT KEEP THE SOUTHWEST BEYOND THE FRAY WITH NO RAINFALL. CISCO